Laparoscopic repair of a migrated adjustable gastric band connecting tube with colonic erosion.

Laparoscopic adjustable gastric bands are a popular and effective surgical option to treat morbid obesity. The overall complication rate is 10-20% and the most common complication is of 'slippage'. Although other complications such as gastric band migration and erosion have been reported, the phenomenon of a migrated gastric band connecting tube eroding into the colon (after port removal) is seldom reported in the literature. In this article we describe such a case of an incidentally found colonic erosion on colonoscopy and describe the subsequent laparoscopic repair, as well as a review of the literature.

A laparoscopic transgastric approach to the treatment of sphincter of Oddi dysfunction postgastric bypass.

Obesity is endemic and bariatric surgery is increasing in an attempt to reduce the physiological and social cost. As the prevalence of bariatric surgery increases, in particular laparoscopic roux-en-Y gastric bypass (LRYGB), the need to investigate and treat subsequent pathology in the gastric remnant and biliary tree will accrue. We describe a novel combined surgical and endoscopic technique addressing the challenges of postoperative anatomy, allowing investigation and treatment of the gastric remnant and biliary tract. We present the case of a patient with sphincter of Oddi dysfunction post-LRYGB who underwent laparoscopic transgastric endoscopic injection of Botox into the ampulla with an excellent symptomatic relief. Subsequent laparoscopic transgastric sphincterotomy allowed definitive treatment and allowed symptom resolution at 6 months follow-up. Laparoscopic transgastric endoscopic investigation and treatment is a novel approach to circumvent the restrictions of post-LRYGB anatomy and may assume greater importance in an ageing obese population.

Optimizing selective cerebral perfusion: deleterious effects of high perfusion pressures.

OBJECTIVE: Selective cerebral perfusion is a proven adjunct to hypothermia for neuroprotection in complex aortic surgery. The ideal conditions for the provision of selective cerebral perfusion, however, including optimal perfusion pressure, remain unknown. We investigated the effects of various perfusion pressures during selective cerebral perfusion on cerebral physiology and outcome in a long-term porcine model. METHODS: Thirty piglets (26.3 +/- 1.4 kg), cooled to 20 degrees C on cardiopulmonary bypass with alpha-stat pH management (mean hematocrit 23.6%), were randomly assigned to 90 minutes of selective cerebral perfusion at a pressure of 50 (group A), 70 (group B), or 90 (group C) mm Hg. With fluorescent microspheres and sagittal sinus sampling, cerebral blood flow and cerebral oxygen metabolism were assessed at baseline, after cooling, at two points during selective cerebral perfusion, and for 2 hours after cardiopulmonary bypass. Visual evoked potentials were monitored during recovery. Neurobehavioral scores were assessed blindly from standardized videotaped sessions for 7 postoperative days. RESULTS: Cerebral blood flow during selective cerebral perfusion was significantly increased by higher-pressure perfusion (P = .04), although all groups sustained similar levels of cerebral oxygen metabolism during selective cerebral perfusion (P = .88). After the end of cardiopulmonary bypass, the cerebral oxygen metabolism increased to above baseline in all groups, with the highest levels seen in group C (P = .06). Intracranial pressure was significantly higher during selective cerebral perfusion in group C (P = .0002); visual evoked potentials did not differ among groups. Neurobehavioral scores were significantly better in group A (P = .0002). CONCLUSION: Selective cerebral perfusion at 50 mm Hg provides neuroprotection superior to that at higher pressures. The increased cerebral blood flow with higher-pressure selective cerebral perfusion is associated with cerebral injury, reflected by high post-cardiopulmonary bypass cerebral oxygen metabolism and poorer neurobehavioral recovery.

Perfusing the cold brain: optimal neuroprotection for aortic surgery.

BACKGROUND: Selective cerebral perfusion (SCP) may enhance the neuroprotective benefits of hypothermia during aortic surgery. However, despite its widespread adoption, there is no consensus regarding optimal implementation of SCP. We used a survival porcine model to explore the physiologic characteristics and behavioral benefits of various protocols involving hypothermic circulatory arrest (HCA) and SCP. METHODS: Thirty pigs (26.3 +/- 1.4 kg), cooled to 15 degrees C on cardiopulmonary bypass, using alpha-stat pH management (mean hematocrit 30%), were randomly allocated to differing brain protection strategies: 90 minutes of HCA (group A); 30 minutes of HCA, then 60 minutes of SCP (group B); or 90 minutes of SCP (group C). Using fluorescent microspheres and sagittal sinus sampling, cerebral blood flow (CBF [mL x 100g(-1) x min(-1)]) and cerebral metabolic rate for oxygen (CMRO2 [mL x 100g(-1) x min(-1)]) were assessed at baseline, after cooling, during SCP (where applicable), and for 2 hours after cardiopulmonary bypass. Neurobehavioral scores were assessed blindly from standardized videotaped sessions for 7 days postoperatively. RESULTS: Cerebral blood flow was significantly higher (p = 0.0001) during SCP (60 and 90 minutes) if preceded by HCA. The CMRO2 was also significantly higher in group B versus group C (p = 0.016) at 60 minutes. The CMRO2 in all three groups rebounded promptly toward baseline after weaning from cardiopulmonary bypass. Postoperative neurobehavioral scores were significantly worse in group A. CONCLUSIONS: Continuous SCP provides the best brain protection overall. However, an initial period of HCA does not seem to impair late outcome; perhaps the elevated CBF and CMRO2 observed reflect a beneficial cerebral response to a recoverable insult. Clearly, 90 minutes of HCA induces permanent brain injury, even in this carefully controlled setting.

Preservation of spinal cord function after extensive segmental artery sacrifice: regional variations in perfusion.

BACKGROUND: Sacrifice of intercostal and lumbar arteries simplifies thoracoabdominal aneurysm surgery and enables endovascular stenting. Little is known about alterations in cord perfusion after extensive segmental artery sacrifice. We explored this question using hypothermia to reduce metabolism. METHODS: Twelve juvenile Yorkshire pigs (mean weight, 22.3 kg) were randomized to segmental artery sacrifice at 32 degrees C or 37 degrees C. Cord integrity was assessed with myogenic-evoked potential (MEP) monitoring. Stepwise craniocaudal sacrifice of segmental arteries was continued until MEP diminution occurred; the last segmental artery was then reopened. Fluorescent microspheres were used to measure spinal cord blood flow (SCBF) at baseline, 5 minutes, 1 hour, and 3 hours after segmental artery sacrifice. Hind limb function was monitored for 5 days. RESULTS: All animals recovered normal hind limb function. At 32 degrees C, more segmental arteries, 16.5 versus 15 (p = 0.03), could be sacrificed without MEP loss. Baseline SCBF at 32 degrees C was 50% that at 37 degrees C (p = 0.003) and remained fairly stable throughout. At 37 degrees C, SCBF to the craniocaudal extremes of the cord (C1 to T3 and L2 to L6) increased markedly (p = 0.01) at 1 hour and returned toward normal at 3 hours. Concomitantly, SCBF fell in the middle portion of the cord (T9 to T13) at 1 hour before returning to normal at 3 hours. CONCLUSIONS: Almost all segmental arteries can be sacrificed with preservation of spinal cord function. No major change occurs in the central cord in normothermic animals, but there is significant transient hyperemia in segments adjacent to extrasegmental vessels. Hypothermia reduces SCBF and abolishes this possible steal phenomenon. Metabolic and hemodynamic manipulation should enable routine sacrifice of all segmental arteries without spinal cord injury.

Avoidance of hemodilution during selective cerebral perfusion enhances neurobehavioral outcome in a survival porcine model.

INTRODUCTION: The ideal hematocrit (HCT) level during hypothermic selective cerebral perfusion (SCP)--to ensure adequate oxygen delivery without excessive perfusion--has not yet been determined. METHODS: Twenty pigs (26.0+/-2.6 kg) were randomized to low or high HCT management. The cardiopulmonary bypass (CPB) circuit was primed with crystalloid in the low HCT group (21+/-1%), and with donor blood in the high HCT group (30+/-1%). Pigs were cooled to 20 degrees C and SCP was carried out for 90 min. During rewarming, whole blood was added in the low HCT group and crystalloid in the high HCT group to produce equivalent HCT levels by the end of the procedure. Using fluorescent microspheres and sagittal sinus sampling, cerebral blood flow (CBF) and oxygen metabolism (CMRO2) were assessed at baseline, after cooling, at two points during SCP (30 and 90 min), and at 15 min and 2 h post-CPB. In addition, a range of physiological and metabolic parameters, including intracranial pressure (ICP), were recorded throughout the procedure. The animals' behavior was videotaped and assessed blindly for 7 days postoperatively (maximum score=5). RESULTS: HCT levels were equivalent at baseline, 2 h post-CPB, and at sacrifice, but significantly different (p<0.0001) during cooling and SCP. Mean arterial pressure, pH and pCO2, and CMRO2 were equivalent between groups throughout. ICP was similar in the two groups throughout cooling, SCP, and rewarming, but was significantly higher in the low HCT animals after the termination of CPB. CBF was similar at baseline, but thereafter markedly higher in the low HCT group. Neurobehavioral performance was significantly better in the high HCT animals (median score 3.5 vs 4.5 on day 3, and 4.5 vs 4.75 on day 7, p=0.003). CONCLUSIONS: Higher HCT levels for SCP produced a significantly superior functional outcome, suggesting that the higher CBF with a lower HCT may be injurious, possibly because of an increased embolic load.

Early clinical and hemodynamic outcomes after stented and stentless aortic valve replacement: results from a randomized controlled trial.

BACKGROUND: Stentless aortic bioprostheses were shown to be hemodynamically superior to earlier generations of stented bioprostheses. Modern stented valve designs have improved hemodynamics. A prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves. Our aim was to determine any differences in early postoperative clinical and hemodynamic outcomes. METHODS: Patients with severe aortic valve stenosis (n = 161) undergoing aortic valve replacement were randomized intraoperatively to receive either the C-E Perimount (Edwards Lifesciences, Irvine, CA) pericardial stented bioprosthesis (n = 81) or the Prima Plus (Edwards Lifesciences) (porcine stentless bioprosthesis (n = 80). Transthoracic echocardiograms were performed at one week and eight weeks postoperatively to assess left ventricular mass (LVM) and transvalvular gradients (TVG). RESULTS: There were no differences between the two groups in baseline characteristics. Cardiopulmonary bypass and ischemic times were longer in the stentless group. Despite similar native aortic annular diameters, the mean size of the prosthesis used in the stentless group was 2.1 mm (SD = 2.8) larger (p < 0.001). Early (30-day) mortality (stentless 3.7% vs stented 2.5%; p = 0.68) and morbidity was similar between groups. Eight weeks postoperatively, LVM (stentless 199 +/- 70 vs stented 204 +/- 66 grams; p = 0.32) and TVG decreased in both groups (mean systolic gradient; stentless 10 +/- 3 vs stented 10 +/- 4 mm Hg; p = 0.54) but there was no significant difference between groups. CONCLUSIONS: Despite longer ischemic times in the stentless group, early postoperative outcomes were similar. Both stented and stentless aortic valve replacement offers excellent hemodynamics and can be achieved with low perioperative mortality.

The fate of the distal aorta after repair of acute type A aortic dissection.

OBJECTIVES: The residual aorta's behavior after repair of acute type A dissection is incompletely understood. We analyzed segmental growth rates, distal reoperation, and factors influencing long-term survival. METHODS: One hundred seventy-nine consecutive patients (70% male; mean age, 60 years) with acute type A dissection underwent aggressive resection of the intimal tear and open distal anastomosis (1986-2003). Hospital mortality was 13.4%. Survivors had serial computed tomographic scans: digitization yielded distal segmental dimensions. Segment-specific average rates of enlargement and factors influencing faster growth were analyzed. Distal reoperations and patient survival were examined. RESULTS: Eighty-nine (57%) patients had imaging data sufficient for growth rate calculations. The median diameters after repair were as follows: aortic arch, 3.6 cm; descending aorta, 3.7 cm; and abdominal aorta, 3.2 cm. Subsequent growth rates were 0.8, 1.0, and 0.8 mm/y, respectively. Initial size of greater than 4 cm (P = .005) and initial diameter of less than 4 cm with a patent false lumen (P = .004) predicted greater growth in the descending aorta, and male sex (P = .05) significantly affected growth in the abdominal aorta. No significant factors were found for the aortic arch. There were 25 distal aortic reoperations (16 patients), and risk of reoperation was 16% at 10 years. Risk factors reducing long-term survival after repair of acute type A dissection included age (P < .0001), new neurological deficit at presentation (P = .04), absence of preoperative thrombus in the false lumen of the ascending aorta (P = .03), and a patent distal false lumen postoperatively (P = .06) but not distal reoperation. CONCLUSIONS: Growth of the distal aorta after repair of acute type A dissection is typically slow and linear. Distal reoperation is uncommon, and late risk of death is approximately twice that of a healthy population.

Thoracic and thoracoabdominal aneurysm repair: is reimplantation of spinal cord arteries a waste of time?

BACKGROUND: The impact of different strategies for management of intercostal and lumbar arteries during repair of thoracic and thoracoabdominal aortic aneurysms (TAA/A) on the prevention of paraplegia remains poorly understood. METHODS: One hundred consecutive patients with intraoperative monitoring of motor evoked potentials (MEP) and somatosensory evoked potentials (SSEP) during TAA/A repair involving serial segmental artery sacrifice (October 2002 to December 2004) were reviewed. RESULTS: Operative mortality was 6%. The median intensive care unit stay was 2.5 days (IQ range: 1-4 days), and the median hospital stay 10.0 days (IQ range: 8-17 days). Potentials remained unchanged during the course of serial segmental artery sacrifice, or could be returned to baseline levels by anesthetic and blood pressure manipulation, in 99 of 100 cases. An average of 8.0 +/- 2.6 segmental artery pairs were sacrificed overall, with an average of 4.5 +/- 2.1 segmental pairs sacrificed between T7 and L1, where the artery of Adamkiewicz is presumed to arise. Postoperative paraplegia occurred in 2 patients. In 1, immediate paraplegia was precipitated by an intraoperative dissection, resulting in 6 hours of lower body ischemia. A second ambulatory patient had severe paraparesis albeit normal cerebral function after resuscitation from a respiratory arrest. CONCLUSIONS: With monitoring of MEP and SSEP, sacrifice--without reimplantation--of as many as 15 intercostal and lumbar arteries during TAA/A repair is safe, resulting in acceptably low rates of immediate and delayed paraplegia. This experience suggests that routine surgical implantation of segmental vessels is not indicated, and that, with evolving understanding of spinal cord perfusion, endovascular repair of the entire thoracic aorta should ultimately be possible without spinal cord injury.

Are stentless valves superior to modern stented valves? A prospective randomized trial.

BACKGROUND: It is presumed that stentless aortic bioprostheses are hemodynamically superior to stented bioprostheses. A prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves. METHODS AND RESULTS: Patients with severe aortic valve stenosis (n=161) undergoing aortic valve replacement (AVR) were randomized intraoperatively to receive either the C-E Perimount stented bioprosthesis (n=81) or the Prima Plus stentless bioprosthesis (n =80). We assessed left ventricular mass (LVM) regression with transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI). Transvalvular gradients were measured postoperatively by Doppler echocardiography to compare hemodynamic performance. There was no difference between groups with regard to age, symptom status, need for concomitant coronary artery bypass surgery, or baseline LVM. LVM regressed in both groups but with no significant difference between groups at 1 year. In a subset of 50 patients, MRI was also used to assess LVM regression, and again there was no significant difference between groups at 1 year. Hemodynamic performance of the 2 valves was similar with no difference in mean and peak systolic transvalvular gradients 1 year after surgery. In patients with reduced ventricular function (left ventricular ejection fraction [LVEF] <60%), there was a significantly greater improvement in LVEF from baseline to 1 year in stentless valve recipients. CONCLUSIONS: Both stented and stentless bioprostheses are associated with excellent clinical and hemodynamic outcomes 1 year after AVR. Comparable hemodynamics and LVM regression can be achieved using a second-generation stented pericardial bioprosthesis. In patients with ventricular impairment, stentless bioprostheses may allow for greater improvement in left ventricular function postoperatively.

Optimal pH strategy for selective cerebral perfusion.

OBJECTIVE: Selective cerebral perfusion (SCP) affords brain protection superior to hypothermic circulatory arrest (HCA) for prolonged aortic arch procedures. Optimal pH strategy for HCA is controversial; for SCP it is unknown. We compared pH strategies during SCP in a survival pig model. METHODS: Twenty juvenile pigs (26+/-2.4 kg), randomized to alpha-stat (n=10) or pH-stat (n=10) management, underwent cooling to 20 degrees C on cardiopulmonary bypass (CPB) followed by 90 min of SCP at 20 degrees C. SCP was conducted with a mean pressure of 50 mmHg and hematocrit of 22.5%. Using fluorescent microspheres and sagittal sinus blood sampling, cerebral blood flow (CBF) and oxygen metabolism (CMRO2) were assessed at the following time points: baseline, after 30 min cooling (20 degrees C), 30 min of SCP, 90 min of SCP, 15 min post-CPB and 2h post-CPB. Visual evoked potentials (VEP) were assessed at baseline and monitored for 2h during recovery. Neurobehavioral recovery (10=normal) was assessed in a blinded fashion for 7 postoperative days. RESULTS: There were no significant differences between the groups at baseline. CBF was significantly higher at the end of cooling, and after 30 and 90 min of SCP in the pH-stat group (P=0.02, 0.007, 0.03). CMRO2 was also higher with pH-stat (P=0.06, 0.04, 0.10). Both groups showed prompt return to values close to baseline after rewarming (P=ns). VEP suggested a trend towards improved recovery in the alpha-stat group at 2h post-CPB, P=0.15. However, there were no significant differences in neurobehavioral score: (alpha-stat versus pH-stat) median values 7 and 7.5 on day 1; 9 and 9 on day 4, and 10 and 10 on day 7. CONCLUSIONS: These data suggest that alpha-stat management for SCP provides more effective metabolic suppression than pH-stat, with lower CBF. Clinically, the better preservation of cerebral autoregulation during alpha-stat perfusion should reduce the risk of embolization.

Aortic arch replacement using a trifurcated graft: simple, versatile, and safe.

BACKGROUND: Hypothermic selective antegrade cerebral perfusion during aortic arch replacement may prevent adverse neurologic sequelae. It can be provided via balloon-tipped catheters or a branched graft sewn to the brachiocephalic vessels. We report a consecutive series of total arch replacement using a trifurcated graft. METHODS: From September 1999 through October 2004, 109 patients underwent nonemergent total arch replacement using this technique. The graft, placed during a period of hypothermic circulatory arrest, was used for selective cerebral perfusion during the arch reconstruction. RESULTS: Adverse outcomes were seen in 9 (8.3%) patients: hospital death in 5 (4.6%), and stroke in 5 (4.6%). Transient neurologic dysfunction was noted in 6 (5.5%) patients. Mean duration of hypothermic circulatory arrest was 31.2 +/- 6.6 minutes and selective cerebral perfusion was 65.3 +/- 20.9 minutes. Reoperation for bleeding was required in 3 (2.8%) patients and prolonged intubation in 15 (13.8%). Median intensive care unit stay was 3 days (interquartile range 2-4; range, 1 to 108) and hospital stay was 9 (interquartile range 8-15; range, 5 to 108). CONCLUSIONS: The trifurcated graft technique results in low rates of perioperative mortality, temporary neurologic dysfunction, and stroke. It may reduce cerebral embolization as it requires no instrumentation of the aortic arch to establish selective cerebral perfusion and, although it mandates hypothermic circulatory arrest to place the graft, this interval is reliably brief enough to fall within accepted safe limits. This strategy leaves no residual arch tissue behind, and allows placement of an elephant trunk proximal to one or more arch vessels if anatomically indicated.

Composite aortic root replacement in acute type A dissection: time to rethink the indications?

OBJECTIVE: The indications for aortic root replacement in acute type A dissection are unclear. We reviewed the immediate and long-term outcome of consecutive patients in a series in which a low-threshold policy of composite aortic root replacement had evolved. METHODS: From a prospectively compiled aortic surgery database, we identified 162 patients who had either supracoronary interposition grafting, Group A (n=89), or composite root replacement, Group B (n=73) for acute type A dissection. Patients receiving total arch replacements were excluded. Operative and clinical details were analyzed and patient survival was compared to an age and gender matched census cohort. Need for reoperation on the proximal or distal aorta was also noted. Follow-up totaled 795.5 patient-years. RESULTS: Hospital mortality rates were identical in both groups (12.3%: 11 deaths in group A; 9 in group B). Chronic pulmonary disease, diabetes, malperfusion, hemodynamic compromise and aortic root dilatation were independent risk factors for hospital death. Actuarial survival estimates at 1, 5 and 10 years were 79% (71-88%), 64% (53-75%), and 55% (41-68%) for group A, and 79% (70-86%), 73% (62-83%), and 65% (52-78%) for group B (P=0.48). Age and operative patency of the ascending false lumen were independent risk factors for death after hospital discharge. Proximal aortic reoperation was required for four patients in group A and none in group B (P=0.085). CONCLUSION: A strategy of replacement rather than repair of the dissected aortic root for specific indications in type A dissection yielded high survival and low proximal reoperation rates. These results support an aggressive policy of composite root replacement in acute type A dissection.

Replacement of a regurgitant pulmonary valve with a stentless bioprosthesis.

Acquired surgical disease of the pulmonary valve is rare. We report a 72-year-old man who presented with subacute endocarditic pulmonary regurgitation. This lesion was surgically corrected with a stentless bioprosthesis. Previously, homografts and various xenografts have been used for replacement of the pulmonary valve both in the pediatric population and in adult patients with congenital heart disease. Pulmonary regurgitation is a rare lesion, but if it is encountered our case demonstrates that it can be successfully and easily treated with pulmonary valve replacement by using a stentless bioprosthesis.

A versatile technique for aortic root replacement without pre-manufactured composite graft: a 12-year experience.

BACKGROUND AND AIM OF THE STUDY: Replacement of the aortic root is the treatment of choice for aneurysmal dilatation. Many modifications of the Bentall technique have been described, as have valve-sparing procedures. The study aim was to determine the outcome of a versatile modification of composite replacement that has been adopted over the past 12 years. Separate graft and prosthetic valve components were used to allow freedom of valve choice and the use of an appropriately sized graft for the distal aortic anastomosis. METHODS: Between January 1990 and March 2002, 59 patients (45 males, 14 females; mean age 56 +/- 14 years) underwent aortic root replacement using this technique. Indications for surgery were elective in 35 patients and emergent (usually type A aortic dissection) in 24. The range of valve prostheses used, their size, and the size of aortic graft used in each case was assessed. Durations of ischemia and cardiopulmonary bypass were recorded, as was postoperative blood loss and subsequent patient progress, including valve-related events, perioperative mortality and actuarial survival. RESULTS: A wide range of aortic graft sizes was combined with both mechanical and tissue valves (from 1-7 mm larger in diameter). Median postoperative blood loss was 550 ml (IQR 400-800 ml). Perioperative mortality was 5.1%. There were no valve- or technique-related deaths, and the median actuarial survival was 13.17 years. During a 12-year follow up there were no proximal aortic reoperations. CONCLUSIONS: This technique had favorable perioperative mortality, produced a secure proximal suture line, and allowed the surgeon free choice of both valve type and size of aortic graft. This minimized tension at the distal suture line, and produced good hemostasis, especially in those patients with fragile dissected tissues.

Pyrexia after cardiac surgery: natural history and association with infection.

BACKGROUND: Pyrexia is common after major surgery, and infection is often an important consideration. To investigate the natural history and association with infection, we performed a prospective observational study. METHODS: From November 2000 to January 2001, we studied 219 patients undergoing cardiac surgery screening daily for wound, respiratory, urinary tract, and other infections. Pyrexia was defined as temperature above 37.5 degrees C. RESULTS: Of 219 patients, 7 intraoperative deaths occurred and 1 patient was excluded because of preoperative endocarditis, leaving 211. The mean age (SD) was 64 (10) years, consisting of 172 male patients (81.5%). The proportion pyrexial on days 1, 2, and 5 was 30.0%, 25.8%, and 10.3%, respectively. More patients undergoing urgent or emergency procedures (17.7% versus 7.8%; P =.03) subsequently developed pyrexia. However, there were no differences in wound infection (3.4% versus 8.3%; P =.13), positive cultures for respiratory (14.7% versus 11.4%; P =.16), urinary tract (5.2% versus 2.0%; P =.09), or other infection (8.6% versus 7.3%; P =.71) in patients experiencing postoperative pyrexia compared with those who did not. CONCLUSIONS: Pyrexia is common after cardiac surgery and resolves in the majority of patients by day 5. Because there is no association between early pyrexia and infection, diagnosis of early postoperative infection by pyrexia alone is insufficient and is better established by clinical assessment with microbiological evidence.

A simple model to predict coronary disease in patients undergoing operation for mitral regurgitation.

BACKGROUND: Coexistent coronary disease can be identified in a third of patients with mitral valve disease. This study aims to evaluate candidate selection strategy using risk factor identification and logistic regression and to develop an additive model for the prediction of coexistent coronary disease. METHODS: The sample is a consecutive series of patients who had mitral repair from 1987 to 1999. Sensitivities and specificities were calculated for each risk factor. Variables for prediction of coronary disease were entered into a univariate analysis, and predictors were entered into a forward and backward stepwise multivariate logistic regression model to form a predictive score. An additive model was derived from transformation of the logistic model. Receiver operating characteristic curves were used to compare discrimination and precision quantified by the Hosmer-Lemeshow statistic. RESULTS: The American Heart Association and American College of Cardiology risk factor identification selection criteria for the 359 patients who had screening coronary angiography yielded 100% sensitivity and 1% specificity. Risk prediction with our logistic model produced a receiver operating characteristic curve area of 0.91 and Hosmer-Lemeshow score of 3.4 (p = 0.9). Similar discriminating ability for our patients was achieved by the Cleveland Clinic logistic model (receiver operator characteristic curve area of 0.79; Hosmer-Lemeshow score of 12; p = 0.1). Our five-item additive model produced receiver operating characteristic curve area of 0.91 and Hosmer-Lemeshow score of 3.81 (p = 0.80). CONCLUSIONS: Simple risk factor identification has excellent sensitivity but is limited by specificity. Logistic regression modeling is an accurate risk prediction method but is difficult to apply at the bedside. Simplicity and accuracy may be achieved by the logistic regression-derived simple additive model.

A method for descending thoracic aortic replacement retaining a posterior strip bearing intercostal vessels.

Operations for aneurysms of the descending thoracic aorta are still fraught with danger. Spinal cord injury remains a major cause of morbidity. Many therapeutic strategies have been suggested to reduce the incidence of this devastating complication, including reimplantation of intercostal vessels. However, reimplantation of intercostal vessels, both individually or in groups, is time consuming and compounded by the absence of a reliable means of identifying which vessels actually supply the cord. We present a technique that allowed inclusion of all potentially important descending aortic branching vessels into the repair leading to a favorable outcome in a series of patients.